Jacques Pornet

Organometalliques (M = Mg, Zn, Al) derivant de bromures α-alleniques: I. Preparation des organometalliques et etude de leur reactivite vis a vis des derives halogenes

Abstract The preparation of organo-magnesium, -zinc and -aluminum compounds from several primary α-allenic bromides, and their structures, stabilities and reactivities towards various halides are described. The organomagnesium compounds react readily with halides in the presence of Li2CuCl4.

Action du propargyltrimethylsilane sur les derives carbonyles en presence de tetrachlorure de titane: nouvelle voie d'acces aux derives chloropreniques.

Resume Propargyltrimethylsilane reacts with carbonyi compounds to produce chloroprenic derivatives in the presence of titanium tetrachloride.

Synthese et reactivite de silanes propargyliques ω-Fonctionnels : preparation de vinylidene-3 oxolannes, oxannes, oxepannes et oxocannes

Abstract The ω-silyloxypropargyltrimethylsilanes regiospecifically react with aliphatic and aromatic aldehydes to lead to vinylidene oxygen-containing heterocycles,such as 3-vinylidene oxolanes, oxanes, oxepanes and oxocanes.

Synthese regiospecifique d'allenes terminaux a partir de propargyltrimethylsilanes simples ou fonctionnels

Abstract Protodesilylation of varied propargyltrimethylsilanes, using boron trifluorideacetic acid as reagent, give regiospecifically terminal allenes with very good yields. Yet, particular ω-functional propargyltrimethylsilanes may lead to vinylsilanes resulting from a ring-closing cyclisation reaction.

Bis(trimethylsilyl)-1,3 alcynes-1 : Preparation a partir de silanes propargyliques et application a la synthese de silanes alleniques α-fonctionnels

Abstract 1,3-bis(trimethylsilyl)-1-alkynes may be obtained from trimethylsilyl propargylsilanes by metallation with n-butyllithium following by reaction with trimethylsilylchloride; these silanes easily react with acetals, in the presence of titanium tetrachloride, to produce α-functional allenyltrimethylsilanes.

Reactivity of some α-and α,γ - unsaturated silanes towards acetals in the presence of a lewis acid.

Abstract α-and α,γ-unsaturated silanes undergo titanium tetrachloride-induced alkylation of acetals.

Action du propargyltrimethylsilane sur les derives carbonyles en presence de fluorure de tetra-n-butylammonium: nouvelle voie d'acces aux alcools α-alleniques.

Resume Propargyltrimethylsilane reacts with carbonyl compounds to produce α-allenic alcohols in the presence of tetra-n-butylammonium fluoride.

Bistrimethylsilyl-1,4 butyne-2: un nouveau reactif pour la synthese de silanes (α-alleniques monofonctionnels et de dienes conjugues bifonctionnels.

Abstract 1,4-Bistrimethylsilyl-2-butyne reacts with acetals, in the presence of titanium tetrachloride, to produce either functional α-allenyltrimethylsilanes (monoreaction) or difunctional conjugated dienes (direaction).

Synthese d'heterocycles oxygenes a groupe vinylidene exocyclique par voie organosilicique - partie II: Preparation de vinylidene-5 dioxannes-1,3

Abstract The α-silyloxypropargyltrimethylsilanes regiospecifically react with aliphatic aldehydes to lead to alkyl-substituted 5-vinylidene-1,3-dioxanes, in a one-pot reaction.

Action du trimethylsilyl-1 butyne-2 sur les derives carbonyles en presence de catalyseurs: synthese d'alcools α-alleniques ou de derives chloropreniques.

Resume 1-trimethylsilyl 2-butyne reacts with carbonyl compounds in the presence of titanium tetrachloride or tetra-n-butylammonium fluoride, to produce mainly α-allenic alcohols; with titanium tetrachloride, it is also possible to obtain chloroprenic derivatives only.